Heatwave induced invertebrate predation reshapes the plankton community

Climate change stressors including warming and heatwaves can alter
zooplankton composition and dominance patterns in shallow lakes, which can
disrupt ecosystem function and curtail ecosystem services. To understand
such changes, we performed a mesocosm experiment with controls reflecting
the present temperature conditions and a treatment reflecting a future
climate change scenario, including heatwaves of 0-8°C. In the future
climate scenario, the predatory invertebrate, Mesostoma exerted a strong
top-down control particularly on Daphnia, resulting in a switch in the
herbivore dominance to Ceriodaphnia. Cyclopoid copepods were the least
affected taxa but showed tendencies to sustain longer into the winter at
elevated temperatures. A complementary predation experiment revealed that
Mesostoma feed at a higher rate on Daphnia than on Ceriodaphnia and
cyclopoid copepods. In addition to the food-chain alterations, the algal
biomass and cyanobacteria increased with warming which has considerable
implications for management of shallow lakes.